Produce or item recognition by hybrid 3d camera and/or multi-spectrum illumination

ABSTRACT

A code reader and method thereof may include capturing monochrome images of a scene by a monochrome imager, and capturing color images of the scene by a color imager aligned with the monochrome imager. Stereo 3D images of the scene may be generated from the monochrome and color images.

BACKGROUND

Grocery stores have greatly improved efficiency by the wide adoption ofbarcode readers that integrate with point-of-sale (POS) systems alongwith price look-up (PLU) databases. The efficiency has made it possibleto reduce cost for grocery stores due to having fewer checkoutattendants and faster checkouts for customers. One area in whichefficiency still suffers is the ability for checkout attendants toprocess produce and various items that are not coded withmachine-readable indicia (e.g., DataBar barcodes, conventional barcode,QR codes, digital watermarks, etc.). Because produce is not alwaysreadily or easily identified by checkout attendants, especially lessexperienced attendants, and produce is difficult or not possible to markwith a machine-readable indicia, checkout attendants are often left withhaving to compare the produce with photographs of possible produce todetermine how much to charge for the produce being purchased via a PLU.Such an identification and look-up process is inefficient and oftenleads to incorrect results, such as when one type of lettuce ismisidentified as a different type lettuce. In addition to being a slowprocess, incorrectly identifying produce and other items leads toincorrect inventory counts in the retail store, thus leading toinefficiency in ordering and potentially loss of perishable items.

Recent developments of produce identification systems have been made.However, these systems often have difficulty due to being unable toseparate background from the produce and/or products. As an example, adedicated color imager and white illumination devices may be used tocapture images for produce or item recognition. Such systems includePicklist Assist by NCR, Toshiba demo by Focal Systems at NRF2019,VeggieVision by IBM, and so on. The main imaging technologies that areused to support these produce recognition systems are computer visionand machine learning. Item color is one of the main features of thesetechnologies. Such conventional data capture technologies mainly uses acolor image sensor and white illumination LEDs. White balance algorithmsare mainly designed for a human's perception. However, for machinevision, useful features are physical features of items (e.g., produce)instead of human perception.

One challenge with the produce recognition systems is that the colorimagers with color image sensors is that the color image sensors do notwork well for scanning machine-readable indicia, which is the mainfunction of code scanners in retail environments. Moreover, thesesystems generally have lower accuracy than desired due to the use ofwhite illumination, have a higher cost, and are less power efficient. Assuch, there is a need for a produce and product image and recognitionsystem that is highly accurate, low cost, power efficient, supportsdigital watermark codes (e.g., DWcode by Digimarc) and othermachine-readable indicia, and integrates with conventional barcodereading systems used with POS systems.

BRIEF SUMMARY

A code reader with a hybrid monochrome imager and a color imager mayprovide for stereo 3D imaging that supports both readingmachine-readable indicia and produce and product identification. Such acode reader configuration provides for imaging conventionalmachine-readable indicia and supports produce and product or itemidentification that is more accurate than existing produce and productidentification systems. The stereo 3D code read has improved powerefficiency, lower cost, and able to be integrated into existing codereading systems, such as top-down code readers. The use of themonochrome imager allows for reading conventional machine-readableindicia and digital watermarks, and may operate in accordance withexisting code reading standards (e.g., illumination of a scene by a deepred illumination signal), while the use of a color imager supportsidentification of produce and other products while in stationary ornon-stationary states. The monochrome imager may also be used to image ascene that is sequentially illuminated by different wavelengths ofstationary items captured images of the scene illuminated by thedifferent wavelengths may be recombined by a computer to produce a moreaccurate color image than possible with RGB color imagers as a de-mosaicengine is not needed. The use of a combination of the monochrome imagerand color imager as a stereo 3D imager along with a pattern generatorenables a point cloud of items to be produced, thereby providing forenhanced produce and item identification by performing a shape analysis.In an embodiment, the results of the various imaging and produce anditem analysis techniques may be used to determine or limit a selectionmenu of possible items for an operator or user of a Point-of-Sale (POS).

One embodiment of a code reader may include a monochrome imager and acolor imager aligned with the monochrome imager to enable a stereo 3Dimage of the scene to be generated by images captured by the monochromeand color imagers.

Another embodiment of a code reader may include a monochrome imager, afirst illumination device configured to output a first illuminationsignal at a first wavelength, and a second illumination device thatoutputs at least one second illumination signal at a second wavelength.A control circuit may be in electrical communication with the monochromeimager, the first illumination device, and second illumination device.The control circuit may be configured to independently drive the firstillumination device and second illumination device to expose themonochrome imager with the first illumination signal and secondillumination signal to capture images of an item. A processor may be incommunication with the control circuit and monochrome imager, and beconfigured to receive and produce a composite color image from thecaptured images illuminated by the first and second illuminationsignals.

One embodiment of a method may include capturing monochrome images of ascene by a monochrome imager and capturing color images of the scene bya color imager aligned with the monochrome imager. Stereo 3D images ofthe scene may be generated from the monochrome and color images.

BRIEF DESCRIPTION OF THE DRAWINGS

Illustrative embodiments of the present invention are described indetail below with reference to the attached drawing figures, which areincorporated by reference herein and wherein:

FIG. 1 is an illustration of an illustrative top-down code readercapable of reading and decoding machine-readable indicia on productlabels and configured with a stereo 3D imaging system for use inautomatically identifying items in accordance with the principlesprovided herein;

FIGS. 2A-2D (collectively FIG. 2) are illustrations of an illustrativeconfiguration of a hybrid stereo 3D camera layout of a code reader andoperation thereof in accordance with the principles herein;

FIG. 3 is an illustration of an illustrative functional operation of amonochrome imager and color imager of the hybrid stereo 3D camera ofFIG. 2;

FIG. 4 is an illustration of an illustrative code reading systeminclusive of an add-on module for produce and item recognition;

FIG. 5 is an illustration of an illustrative hybrid 3D camera includinga monochrome imager and color imager;

FIG. 6 is a spectrum graph of multi-spectrum illumination sources orsignals by different illumination devices for use with a monochromeimager that are used to improve identification of items by a code readerusing a multi-spectral analysis;

FIG. 7 is a block diagram of an illustrative circuit of a monochromeimager using different wavelength illumination devices for use incapturing images of items to perform identification thereof;

FIG. 8 is a timing diagram of a monochrome imager and multiple colorillumination devices used to illuminate a scene captured by themonochrome imager;

FIG. 9 is a timing diagram of a continuous image output though an FPGAby a micro control unit without affecting barcode and DWM reading;

FIG. 10 shows images of illustrative color panels captured by amonochrome imager using red, green, and blue LEDs to illuminate thecolor panels along with a composite image produced by a combination ofthe captured monochrome images;

FIG. 11 is a block diagram of an illustrative circuit including amonochrome and color imager along with red, green, and blue LEDs forilluminating a scene to be captured by the imager(s);

FIGS. 12A-12D are timing diagrams of illustrative illumination and imagecapture processes for capturing continuous and on-demand color images ofa scene;

FIG. 13 is a timing diagram of an illustrative color image captureprocess by a monochrome imager and a color imager using red and whiteLEDs;

FIG. 14 is a spectral diagram of illustrative wavelengths of a magentaLED for use with an embodiment of an imaging system described herein;

FIG. 15 is a flow diagram of an illustrative barcode and DWM imagingprocess;

FIG. 16 is a flow diagram of an illustrative produce and itemrecognition process; and

FIG. 17 is a flow diagram of an illustrative produce and itemrecognition process using multi-spectral analysis.

DETAILED DESCRIPTION OF THE DRAWINGS

Code readers are widely used in retail environments. In some cases, suchas produce (e.g., grapes, apples, etc.) and items (individually andcollectively “objects”), it is not possible or not consumer-acceptableto stick machine-readable indicia onto the items (e.g., produce,products, etc.) so other techniques to determine the items so as toimprove productivity of operators or shoppers in completing atransaction for the items. One such technique is to perform imageprocessing so as to automatically identify the un-coded items. However,there are some challenges that exist in imaging the items. Suchchallenges may include, but are not limited to:

(1) Item Color: Item color is a primary feature of object recognitionalgorithms. Accurate image color balance changes according to ambientlight and to interaction from other illumination signals, such as redLEDs used by a code scanner. As provided herein, one solution is to useactive pulsed white or multiple spectrum illumination synchronized withthe scanner.

(2) Image Background: Objects other than the item itself, such asbackground objects (e.g., surface on which an object rests when beingimages) is not desired and real-time background removal is difficult. Asprovided herein, one solution is to use a color imager and monochromeimager pair to be able to generate a three-dimensional (3D) point cloudfor localizing the object.

(3) Color Resolution: In some cases, available color resolution whenusing three color illumination (e.g., RGB) is not enough to separateobjects with similar color signatures. As provided herein, an increasein the number of colors available for use in illuminating objects (e.g.,multi-spectrum LEDs) may be used to increase the object recognitionrate.

(4) Cost and Energy Efficiency: For all functions of code scanningsystems, including read barcode, read digital watermark (DWcode), andcolor features of items, cost and energy efficiency is desirable. In anembodiment, one solution includes using a single monochrome imager andRGB LEDs for the functions (i.e., barcode reading, DWcode, and colorfeature recognition). Even with both color and monochrome imagers withwhite LEDs only, a green notch optical filter on a monochrome imagerside provides good performance for DWcode reading.

With regard to FIG. 1, an illustration of an illustrative top-down codereader system 100 capable of reading and decoding machine-readableindicia on product labels and configured with a stereo 3D imaging systemfor use in automatically identifying items (e.g., produce) in accordancewith the principles provided herein. In an embodiment, a reader head 102may include a pair of imagers, including a monochrome imager and a colorimager (see FIG. 2A) configured in a stereo 3D configuration so as tocapture 3D images of items disposed on an imaging surface 104 orotherwise being positioned within a field-of-view of the reader head102. As an example, the produce may be lettuce 106, and the code readersystem 100 may be configured to control illumination devices, such aslight emitting diodes (LEDs) having different wavelengths, to outputillumination signals 108 to illuminate a scene 110 at the imagingsurface 104 with produce or items disposed. The monochrome imager mayhave a field-of-view that includes the produce/item to capture images ofthe produce/items scene 110 being illuminated by the differentwavelengths. A processor of the system 100 may combine the capturedimages to form a color image that is more accurate than is possible by acolor imager. The processor may process the images and assist anoperator or user of the system 100 to automatically identify theproduce/item captured in the images, and the system 100 may communicateinformation associated with the identified produce/item to apoint-of-sale system (not shown) for displaying on a user interface forthe user to confirm and/or select.

It should be understood that the coder reader system 100 may includeadditional imagers at different locations in addition to the reader head102, such as within the horizontal platter and/or vertical bonnet tocapture images for additional views of the items of a bi-optic scanner.Some embodiments may also include arrangements with different views thatare desirable for self-checkout systems. Such other imagers may includemonochrome imagers and/or color imagers, including hybrid pairs ofimagers, as described herein. Thus, it should also be understood thatembodiments of the disclosure having the monochrome imager and colorimager pair are not limited to being disposed only in a top-down readerarrangement as shown in FIG. 1, but also within other arrangements of acheckout system (e.g., assisted as well as self-checkout), standalonetop-down readers, hand-held readers, and other types of code readersknown in the art.

With regard to FIGS. 2A-2D (collectively FIG. 2), illustrations of anillustrative configuration of a hybrid stereo 3D camera layout 200 a ofa code reader in accordance with the principles herein is shown. Inparticular, FIG. 2A shows the 3D camera layout 200 a with variouscomponents, and FIGS. 2B-2C show active components (using solid lines)and non-active components (using dotted lines) for different operationalmodes that will be described further hereinbelow. In an embodiment, acode reader with the 3D camera layout 200 a may be configured (e.g.,programmed or hard wired) to be in a code reading mode, item identifymode, and specific illumination mode manually, automatically, orsemi-automatically. For example, if an item is positioned within afield-of-view of the 3D camera layout 200 a and a machine-readableindicia is not identified within a timer period (e.g., 2 seconds), thenthe code reader may automatically determine whether the item is movingor not and then initiate an item identification process. Alternativeprocesses may be utilized, as well.

As shown in FIG. 2A, the hybrid stereo 3D camera layout 200 a mayinclude a left imager 202 and right imager 202. In an embodiment, theleft imager 202 is a monochrome imager and the right imager 204 is acolor imager. It should be understood that the left imager 202 mayalternatively be a color imager and the right imager 202 may be amonochrome imager. That is, the layout 200 a may be a mirror layout asshown, and provide the same or analogous functionality as the layout 200a, as presented.

The left imager or monochrome imager 202 may have four green or otherwavelength sub-sensors 206 a-206 d (collectively 206) so as to form amonochrome (i.e., single color) imager, and the right imager or colorimager 204 may have three colored sub-sensors, including red 208 a,green 208 b/208 c, and blue 208 d (collectively 208) sub-sensors so asto form a multi-spectral or color imager. It should be understood thatalternative color sensors or locations of the color sensors may beutilized in forming the color imager. Each of the sensors 202 and 204may be configured with quadrants of the sub-sensors 206 and 208.Alternative configurations and/or numbers of sub-sensors may be utilizedin accordance with the principles described herein. For example, theconfiguration may be a triangular configuration with three sub-sensors.The left and right imagers 202 and 204 may include additional hardware,such as memory, analog-to-digital (A/D) converters, data storagedevices, data communication devices, and/or otherwise that are not shownto convert, store, and communicate illumination data generated by thesub-sensors 206 and 208.

The layout 200 a may further include a set of red illumination devices(e.g., LEDs) 210 a-210 d (collectively 210) that are used to illuminatea scene for the monochrome imager 202, as described with regard to FIG.2B. As understood in the art, the red illumination devices 210 may beconfigured to meet barcode reading standards that are established by anindustry group that defines printing, illumination, and imagingstandards of machine-readable indicia. As such, the red illuminationdevices 210 may output specific wavelengths, such as 670+/−10 nmwavelengths, as shown. Alternative wavelengths may be utilized dependingon the use and specifications of the system.

In addition, for imaging color scenes by the color imager 204, whiteillumination devices 212 a-212 d (collectively 212) may be provided. Thewhite illumination devices 212 may be turned on to create multi-spectrallighting for the color imager 204 to collect images of items beingimaged by the color imager 204, as further described with regard to FIG.2D. A pattern projector 214, which may be optional, may be provided toilluminate the scene with a pattern of light so that a 3D image of thescene may be better determined, as described with regard to FIG. 2C.

In an embodiment, a number of image sensor pairs may be utilized,including the non-limiting pairs of image sensors provided in TABLE I:

TABLE I IMAGE SENSOR PAIRS Monochrome Imager Color Imager ManufacturerOV9282 or OV9285 OV9782 OmniVision (1328 × 1120) (1280 × 800)Technologies OG02B1B OG02B10 OmniVision (1600 × 1200) (1600 × 1200)Technologies AR144CSSM AR0144CSSC ON Semiconductor EV76C560ABT-EQVEV76C560ABT-EQV E2V AR0144CSSM AS0142AT with ON Semiconductor (YUVoutput)

The code reader may operate in two modes, including (i) imaging anddecoding of machine-readable indicia, and (ii) performing produce anditem imaging and optionally recognition. To support these functions,different configurations of the imaging system and control/processingsystem may be utilized. Different illustrative configurations of theimaging system are shown in FIGS. 2A and 5, and different illustrativeconfigurations of the control/processing system are shown in FIGS. 4, 7,and 11, where the imaging and control/processing systems may beconfigured to operate specifically in conjunction with the respectivedesigns (i.e., a control/processing system matches the configuration ofthe imaging system).

With specific regard to FIG. 2B, when the code reader is being used toperform reading of machine-readable indicia, the monochrome imager 202is activated along with the red illumination devices 210. The remainderof the electronic devices or components, including the color imager 204,white illumination devices 212, and pattern projector 214 are inactive.

With specific regard to FIG. 2C, when the code reader is being used toperform produce and/or item recognition and a 3D image is desired toassist in determining a shape of the product and/or item, the monochromeimager 202, color imager 204, and the pattern projector 214 may beactivated. It should be understood that the pattern projector 214 may behelpful by providing structured light that complex shapes, which areoften found with items in grocery stores, may be determined and used tohelp identify the produced or item. The remainder of the electronicdevices, including the red illumination devices 210 and whiteillumination devices 212, are inactive. Because the left and rightimagers 202 and 204 are positioned to capture 3D images, the image datacollected by each of the imagers may be processed together so as togenerate 3D point clouds of the items being imaged by code reader.

The pattern projector 214 may be used, at least in part, to enable thecode reader to assist in removing the background of the scene, in thiscase the work surface or scanner surface on which the items are placedfor the code reader to scan and/or image the items. The code reader maybe a top-down code reader. The monochrome and color imagers 202 and 204are able to see the light pattern similarly in that intensity andlocation of the light pattern may be sensed in about the same manner byeach of the imagers 202 and 204. For example, a pattern of light outputby the pattern projector 214 may be imaged onto the work surface withoutany objects thereon to enable determining a baseline work surface.Thereafter, when scanning items, the pattern of light that matches thebaseline background scan may be used to enable the background to bedetected and eliminated from other image data to reduce image processingefforts and to improve produce and item recognition efficiency.

In generating the 3D point clouds, the system may use (i) data capturedby the imagers 202 and 204 with ambient or non-ambient lighting and/or(ii) data captured by the imagers 202 and 204 with structured lightproduced by the pattern projector 214 and illuminated onto the produceand/or item being imaged. The 3D point clouds may be used to compareagainst a database of 3D point clouds inclusive of shapes of known itemsto assist with determining a specific produce or item or a class ofproduce or item. If, for example, the 3D point cloud is in the shape ofa banana, for example, items that are not in the shape of a banana(e.g., apples, pears, etc.) may be eliminated from possible matches ofthe produce being imaged using the configuration of FIG. 2C. While 3Dpoint clouds may be produced by the code reader in assisting indetermining items, it should be understood that any other type ofalgorithm that may be produced to be used in determining 3D objects.

With specific regard to FIG. 2D, when the code reader is being used toperform produce and item recognition by using color, the color imager204 and white illumination devices 212 may be activated while the othercomponents may be inactive. The color imager 204 may be used withstationary or moving objects as a result of each of the colorsub-sensors being simultaneously used to capture an image of a scenesuch that each of the colors of the entire scene are captured in asingle frame. Color of items may be used to further distinguish oneproduce or item from another. For example, yellow bananas may bedistinguished from green lettuce and red apples.

With regard to FIG. 3, an illustration of an illustrative functionaloperation of a monochrome imager 302 and color imager 304 of the hybridstereo 3D camera of FIG. 2 is shown. In an embodiment, the hybrid stereo3D camera may be configured onto a top down code reader. The hybridstereo 3D camera may be configured onto any other type of code readerand at any orientation in other embodiments. The imagers 302 and 304 areconfigured to provide for 3D image data collection of a scene at whichthe imagers 302 and 304 are arranged to view. In an embodiment, aprojector 306 that projects structured light or a light pattern onto thescene may be included. The scene may include a scanner window 308 onwhich items may be placed for the imagers 302 and 304 to collect imagedata.

As shown, the monochrome imager may collect image data within afield-of-view defined by a monochrome image region 310, and the colorimager may collect image data within a field-of-view defined by a colorimage region 312. The two image regions 310 and 312 are shown to beslightly offset based on the distance between the imagers 302 and 304.In operation, the projector 306 may project a light pattern onto thescanner window 308, and the imager(s) 302 and/or 304 may collect imagedata of the light pattern being displayed on the scanner window 308.During scanning operation of items, the background, which in this caseis the scanner window 308, may be selectively removed from capturedimages so that the items may be processed for comparison purposes inidentifying the items.

With regard to FIG. 4, an illustration of an illustrative code readingsystem 400 inclusive of an add-on module for produce and itemrecognition is shown. The system 400 may include a monochrome imager 402and a color imager 404, which may be respectively positioned on left andright sides. An FPGA 406 may be in electric communication with theimagers 402 and 404, and be configured to control timing of componentsof the system 400. For example, the FPGA 406 may be configured tocontrol operation of one or more red illumination devices 408 and causethe monochrome imager 402 to collect image data when the redillumination devices 408 are activated. A micro processing unit (MPU)410 may be configured to perform decoding of machine-readable indicia(e.g., barcodes) and digital watermarks by receiving image datacollected by the monochrome imager 402 including the machine-readableindicia and barcodes.

To provide for produce and item recognition, the color imager 404, whiteillumination device(s) 412, and micro processing unit 414 may be used toform a produce vision item recognition add-on circuit 416. The FPGA 406may be in communication with the white illumination device(s) 412 tocontrol operation thereof and be in communication with the MPU 414 tocommunicate data therewith. In an embodiment, the MPU 414 may beconfigured to transform captured color image data from an RGB dataformat to YUV data format, thereby enabling monochromatic image datacaptured by the monochrome imager 402 to be more readily processed withimage data captured by the color imager 404. A computing device orsystem 418, such as a computer, server, or Raspberry Pi computer boardmay be configured to perform 3D and color image processing to performproduce and/or item recognition. The computing device 418 may be incommunication with the MPU 414 via a communications channel 420, such asa USB or Ethernet communications bus. The computing device 418 mayfurther be in communication with a point-of-sale host computer 422 so asto provide produce and/or item recognition information, such as name(s),identifier(s), and/or other information for the POS host computer 422 toadd to a purchase and/or present to an operator or user for selection.

A number of internal communications paths 424 a, 424 b, and 424 c, suchas MIPI serial interfaces, may be used to enable the FPGA 406 tocommunicate with the monochrome imager 402 and the MPU 414, and enablethe MPU to communicate with the color imager 402. It should beunderstood that alternative interfaces may be utilized in accordancewith the principles described herein. However, the MIPI serial interfaceis a standard, low-cost interface that is sufficient for handling datacommunication as provided herein.

Because identification of items can be challenging depending on the typeof produce or items, an increase in color or spectrum may extend fromthree wavelengths (i.e., RGB) to more than three (e.g., between 4 and10) by using additional color illumination devices for the monochromeimager to capture when imaging a scene. With regard to FIG. 5, anillustration of an illustrative hybrid 3D camera 500 including amonochrome imager 502 and color imager 504 is shown. Color illuminationdevices (e.g., LEDs) 506 a-506 j (collectively 506) may be disposed inproximate location to the monochrome imager 502. The number colorillumination devices 506 may be any number, and have distinctwavelengths such that color of a produce or item is able to beidentified more easily as spectral analysis may help in distinguishingone type of produce from another, for example, over each of the distinctwavelengths. Red illumination devices 508 a-508 d (collectively 508) mayalso be provided for capturing images of machine-readable codes, aspreviously described. The camera 500 may also optionally include apattern projector 510. It should be understood that alternativeconfigurations that provide for the same or similar functionality may beprovided, as well.

In operation, a 3D point cloud may be generated by collecting andprocessing image data generated by the monochrome and color imagers 502and 504 arranged in the stereo 3D configuration capturing images of thescene. Thereafter, the color illumination devices 506 may be cycled oneat a time and the monochrome imager 502 may capture an image of thescene while each of the respective devices 506 with the differentwavelengths are illuminated. In the case of cycling the colorillumination devices 506 and imaging the scene with the monochromeimager 502, the produce or item is to remain stationary since movementwould result in a blurred image between successively captured imageframes by the monochrome imager 502.

After calibration with the image sensors 502 and/or 504 being used so asto decouple a learning algorithm from the specific image sensor(s) sothat an item model database is not sensor dependent, theregions-of-interest (ROIs) from the point clouds may be used for produceand item recognition. The learning algorithm may be performed by thecomputer 418 of FIG. 4, for example.

In performing a stereo 3D disparity calculation, camera intrinsic datamay be saved on an imager board, and stereo calibration data may besaved on a board used by the code reader. Thereafter, image data fromthe monochrome imager 402 may be communicated to a recognition moduleexecuting on the computer 418. The image represented by the image datamay be rectified. The image data from the color imager 404 may becommunicated to the computer 418. The image data may be colorde-mosaiced and converted to Y, which may be rectified. Both themonochrome images and color images are CENSUS transformed to remove thegray scale dependence for disparity matching. The color sensor andmonochrome sensor may have different resolution (e.g., higher f # andbetter spatial resolution) and color sensor 404 may be used for 3Dimaging and may have lower f # and fewer pixels. As understood in theart, a higher f # results in a smaller or narrower aperture and deeperdepth-of-field, while a lower f # results in a larger or wider apertureand shallower depth-of-field. In an embodiment, the color imager mayhave an f # of 2.8, while the monochrome imager may have an f # of 5,which enables the monochrome imager to be used for imagingmachine-readable indicia at a wider range of distances from the codereader, for example.

Feature recognition may use a visual pattern recognition (ViPR) or deeplearning algorithm applied to known regions-of-interest. In the case ofmultiple spectrum data, more color data instead of RGB only may beavailable for recognition of the items.

With regard to FIG. 6, a graph of an illustrative multi-spectrumillumination 600 by different wavelength illumination devices for usewith a monochrome imager to improve identification of items by a codereader using a multi-spectral analysis is shown. Wavelengths 602 a-602 k(collectively 602) of each of the respective color illumination devicesare shown on the graph. The wavelengths 602 may include 395 nm, 420 nm,460 nm, 500 nm, 550 nm, 590 nm, 620 nm, 660 nm, 720 nm, 840 nm, and 940nm. It should be understood that alternative number and/or wavelengthsmay be utilized to provide for the same or similar functionality. Withfurther regard to FIG. 4, by including multiple MPUs 410 and 414, onededicated to the monochrome imager 402 and one optionally dedicated tothe color imager 404, it is possible to image and process color imagedata captured by the color imager 404 for items that are moving. Ifadditional color content is desired, then the produce or item may bestopped from moving and the additional color illumination devices may beutilized to improve the ability to identify the produce or item.

To improve efficiency in capturing accurate color images efficiently bycode readers, two non-limiting configurations and techniques may beused, including (i) a single monochrome imager that cycles throughcapturing images of a scene that are illuminated by red, green, and blueillumination signals, and (ii) a single monochrome imager and a singlecolor imager that capture images of a scene that is simultaneouslyilluminated by red, green, and blue illumination signals. As previouslydescribed, the use of a single monochrome imager that successivelycycles through different color illumination signals can be used forstationary items (e.g., produce), while a color imager thatsimultaneously illuminates a scene with multiple color illuminationsignals may be used for items in motion without resulting in blurredimages of the item.

With regard to FIG. 7, a block diagram of an illustrative imagingcircuit 700 of a code reader is shown. Such an imaging circuit 700 maybe disposed within a code reader, such as a top-down reader of a fixedretail scanner, at one or more locations within a fixed retail scanner(e.g., bi-optic, single plane, etc.), or peripheral devices (e.g.,handheld scanners, overhead scanners, etc.), or combinations thereof.The imaging circuit 700 may also be incorporated into other types ofcode readers (e.g., mobile computers, industrial scanners, etc.) asknown in the art.

The imaging circuit 700 has a single MCU or MPU 702 that is incommunication with an FPGA 704. The MPU 702 may be in communication witha monochrome imager 706 that includes an f #5 lens that provides alonger depth-of-field (DOF) than typical monochrome imagers use so as tobetter support cycling through different color illuminations of a scene.The FPGA 704 may be utilized to coordinate timing of the monochromeimager 706 with illumination by different colored illumination devices,including a red illumination device (e.g., LED) 708 a, greenillumination device 708 b, and blue illumination device 708 c(collectively 708). The red illumination device 708 a may output anillumination signal at 660 nm, green illumination device 708 b mayoutput an illumination signal at 540 nm, and blue illumination device708 c that outputs an illumination signal at 460 nm. Alternative colorsand/or wavelengths may be utilized.

The FPGA 704 may be in communication with the MPU 702 via acommunications path 710, which may be an MIPI serial interface. The MPU702 may be in communication with the monochrome imager 706 via a serialinterface 712 for control registers of the monochrome imager 706. TheFPGA 704 may be in communication with the monochrome imager 706 via acommunication path 714 to trigger the monochrome imager 706 based ontiming of the illumination devices 708.

More generally, and in operation, a code reader with the imaging circuit700 may include the monochrome imager 706, first illumination device 708a configured to output a first illumination signal at a firstwavelength, and second illumination device 708 b that outputs at leastone second illumination signal at a second wavelength. A controlcircuit, such as the FPGA 704, may be in electrical communication withthe monochrome imager 706, the first illumination device 708 a, andsecond illumination device 708 b. The control circuit may be configuredto independently drive the first illumination device 708 a and secondillumination device 708 b to expose the monochrome imager 706 with thefirst illumination signal and second illumination signal to captureimages of an item. A processor, such as the MPU 702, may be incommunication with the control circuit and monochrome imager 706, and beconfigured to receive and produce a composite color image from thecaptured images illuminated by the first and second illuminationsignals.

The imaging circuit 700 may further include a third illumination device708 c that outputs at least one third illumination signal at a thirdwavelength. The control circuit may be configured to independently drivethe third illumination device 708 c to expose the monochrome imager withthe third illumination signal to capture an image of the item. Theprocessor may further be configured to produce a composite color imagefrom the captured images illuminated by the first, second, and thirdillumination signals.

In an embodiment, the control circuit may further be configured to causethe monochrome imager 706 to capture an image with ambient light whennone of the first, second, or third illumination devices 708 areactively illuminating. The processor may further be configured to offsetthe composite image with the image captured with ambient light. Theimages of the item captured with each of the first, second, and thirdillumination signals are to be captured with the item being in the same,stationary position.

With regard to FIG. 8, a timing diagram of an image capture process 800for performing barcode and color image capture by a monochrome imager isshown. A number of control signals and illumination signals may be usedas part of the process 800. The process 800 may have different modes,including a barcode reading mode 802 a, capture mode 802 b, and barcodereading mode 802 c. In an embodiment, the barcode reading modes 802 aand 802 c are the same. The two modes 802 a and 802 c may be differentin alternative embodiments. During the barcode reading mode 802 a, a redillumination signal used to illuminate a machine-readable indicia (e.g.,barcode) may illuminate a scene for a monochrome imager, such as shownin FIG. 7, to capture an image the red illuminated machine-readableindicia.

During the color image capture mode 802 b, the red, green, and blueillumination signals may illuminate the scene including items in asequential mode to enable the monochrome imager to capture image datawhen the different colored illumination signals are illuminating thescene. As previously described, if the different color illuminationsignals sequentially illuminate the scene, then the produce and/or itemhas to remain stationary so as to avoid blurring, and each of theillumination signals illuminate the scene distinct from one another.Monochrome images of the scene with the different color illuminationsignals may be captured, and a composite image (e.g., aggregate image)that includes each of the different illumination signals may be formedthereafter to form a color image.

In performing the process 800, an imager trigger control signal 804 maybe used to trigger or turn on the monochrome imager. Illuminationcontrol signals 806, 808, and 810 may be used to turning ON and OFFdifferent illumination devices, including red, green, and blueillumination devices. An FPGA request signal may be used to cause thecolor image capture mode 802 b to occur so as to capture image dataincluding red, green, blue, and ambient lighting conditions of a scenein which items are positioned. An imager register update may updatesignal 814 may be used to update exposure and gain of the imager.

In operation, a monochrome imager may be configured to sequentiallycapture images with the different colored illumination signals,including green, blue, red, and ambient lighting. During the ambientlighting, no active lighting illuminates the scene. A special filter maybe applied to a captured ambient image with a window size of 3×3 pixels.Differences between red and ambient image data, green and ambient imagedata, and blue and ambient image data may be calculated. Thereafter, acalibrated color gain may be applied to the red and blue images. Theresult is a color image for both recognition and visual purposes. Moregenerally, a color recovery process when using a monochrome imager mayinclude (i) capture an ambient image (medium filter with 3×3), (ii)capture active illumination images, (iii) calculate differences of thecolor and ambient captured image data, and (iv) apply color gain fromcolor calibration.

With regard to FIG. 9, a timing diagram of an alternative image captureprocess 900 is shown. The image capture process 900 may include abarcode reading mode 901 a, image capture mode 901 b, and barcodereading mode 901 c. The image capture mode 901 b is used to enable amonochrome imager to capture images with different color illumination ofa scene for use in identifying items within the scene.

A number of signals are shown to include an imager trigger signal 902that is used to capture images of a scene during different lightingconditions, including (i) red and blue, (ii) red, (iii) green, (iv)blue, and (v) ambient. Image or frame data at each of the lightingconditions may be processed thereafter. A red illumination controlsignal 904, green illumination control signal 906, and blue illuminatecontrol signal 908 may be used to turn ON and OFF different illuminationdevices to illuminate the scene with different colors. An ambientillumination control signal 910, which may or may not be an actualsignal, may occur when each of the red, green, and blue control signalsare turned OFF such that there are no active illumination signals beingilluminated onto the scene during those time periods. An FPGA requestcontrol signal 912 may define a frame during which a color image capturecycle is being performed. An image output signal 914 may be used tooutput image data from the imager to the FPGA or other electronicdevice, where the output data includes image or frame data capturedduring the different color illuminations that illuminated the scene. Thedifferent color illuminations may include (i) red and blue, (ii) red,(iii) green, (iv) blue, and (v) ambient illumination signals. The use ofthe imaging process 900 may allow for continuous image output through anFPGA by a micro control unit (MCU), which is often used as a WebCamcontroller, without affecting barcode and digital watermark reading bythe code reader using a single monochrome imager.

With regard to FIG. 10, a set of images 1000 including an illustrativecolor panel 1002 with different images, including a red illuminatedimage 1004 a, green illuminated image 1004 b, and blue illuminated image1004 c, along with a composite color image 1004 d (represented in grayscale, but understood to be color produced by a combination of thecaptured monochrome images) is shown. Because the different colors atdifferent wavelengths react different with the different color panels,which may include sub-portions with different colors, a monochromeimager with the same color sub-sensors may sense the color panel 1002with different illumination intensities depending on the illuminationsignal being used.

In an embodiment, a color calibration may be performed. The colorcalibration may be performed using the following equation:

Vp=(Ia*R+B)+Ii×Ri(background and signal),

where Vp: pixel value,

Ia: ambient incident light on the pixel,

R: reflection of ambient light on the item corresponding to the pixel,

Ii: active illumination (i=R, G, B) incident light on the pixel, and

Ri: reflection of active illumination (i=R, G, B) on the itemcorresponding to the pixel.

For calibration, a gray target may be used to capture multiple images(e.g., 30 images) with only ambient illumination (i.e., no activeillumination). The ambient images may then be averaged to generate animage Img1. Multiple images (e.g., 30 images) may also be captured withactive illumination (e.g., R or G or B) and ambient illumination. Animage difference and average of all pixels may be computed to be IcR,IcG, IcB variables that can be used to perform a color balance of theimage data.

IcR=Img2(R)−Img1(R),

IcG=Img2(G)−Img1(G),

IcB=Img2(B)−Img1(B).

Using green as a reference, gain of red (GainR) and gain of Blue(GainB), so that:

IcR*GainR=IcG=IcB*GainB (color balanced), where GainR and GainB arecalibrated and balanced color gain.

With regard to FIG. 11, a block diagram of an illustrative circuit 1100including a monochrome imager 1102 a and color imager 1102 b(collectively 1102) along with red, green, and blue illumination devices(e.g., LEDs) 1104 a, 1104 b, and 1104 c (collectively 1104) forilluminating a scene to be captured by the imager(s) 1102 is shown. AnMPU 1106 and FPGA 1108 may be included to control functionality of theimagers 1102 and illumination devices 1104. By including the colorimager 1102 b, color images without motion blur may be captured. Thecircuit 1100 may configured to use the monochrome imager 1102 a when theproduce or item being scanned is stationary (e.g., on a flat scanningsurface) and color imager 1102 b when the produce or item is moving(e.g., on a conveyer belt). The MPU 1106 may communicate with the twoimagers 1102 via communication pathways, where the MPU 1106 communicatesimager-C register control signals to the color imager 1102 b andimager-M register control signals 1114 to the monochrome imager 1102 a.The circuit 1100 may be disposed within a code reader as previouslydescribed to decode a machine-readable indicia and/or digital watermarkand/or for item identification (e.g., produce identification).

With regard to FIGS. 12A-12D, timing diagrams of illustrativeillumination and image capture processes for capturing continuous andon-demand color images of a scene is shown. In being continuous, themonochrome imager and color imager is periodically exposed to captureimages of a scene. FIG. 12A provides a control signal process 1200 a forcontinuous color image output. The color imager exposure signaling 1202a is coordinated to capture images of a scene when illuminated by red,blue, and green illuminations 1204 a, 1204 b, and 1204 c (collectively1204), as shown. The monochrome imager exposure signaling 1202 b iscoordinated to capture images of the scene when illuminated by red andblue illuminations 1204 a and 1204 b. The exposure of the color imageris longer than the monochrome imager as the red and blue illuminations1204 a and 1204 b are aligned with one another and ON for 150 μs and thegreen illumination 1204 c is turned ON for 150 μs after the red and blueilluminations 1204 a and 1204 b are turned OFF. The timing of the redand blue illuminations 1204 a and 1204 b may be continuous with thegreen illumination 1204 c. It should be understood that the duration ofthe illuminations 1204 may be different than for 150 μs.

FIG. 12B provides a control signal process 1200 b for color image outputon-demand. In this process 1200 b, rather than the color imager beingperiodically exposed to the scene, the color imager is controlled toturn ON in an on-demand manner such that the color imager may becontrolled to be turned ON at any time in coordination with theillumination devices.

FIG. 12C provides a control signal process 1200 c for color image outputon-demand with only red for barcode and digital watermark reading. Inthis process 1200 c, rather than the monochrome imager beingperiodically exposed to the scene with red and blue illuminationsignals, the monochrome imager captures the scene with only redillumination signals. The color imager is exposed in an on-demand manneras was performed in FIG. 12B.

FIG. 12D provides a control signal process 1200 d for color image outputon-demand with only magenta for barcode and digital watermark reading.In this process 1200 c, rather than the monochrome imager beingperiodically exposed to the scene with red illumination signals, amagenta light source (e.g., magenta LED) may be used such that themonochrome imager captures the scene with only magenta illuminationsignals. The color imager is exposed to capture an image of the scene inan on-demand manner as was performed in FIG. 12B. The magenta LED may bean off-the-shelf magenta LED produced by Edison, and, as shown in FIG.14, and have spectral characteristics 1400 as provided by blue and redLEDs. By using magenta, only two illumination devices, a magenta LED anda green LED, may be utilized, thereby saving cost of components andassembly.

With regard to FIG. 13, a timing diagram of an illustrative process 1300that includes color image capture by a monochrome imager and a colorimager using red and white LEDs is shown. In this process 1300, amonochromatic image trigger 1302 may be used to cause the monochromeimager to turn ON while a red illumination signal 1304 is ON so that ascene in which a machine-readable indicia is located is illuminated bythe red illumination. A color imager trigger signal 1306 may be turnedON to cause a color imager to capture an image of a scene when a whiteillumination signal causes a white LED to be turned ON. A capturerequest signal 1310 may cause the color imager to be selectively turnedON in response to the color imager trigger signal 1306. It should beunderstood that the color imager may be controlled in an on-demand orcontinuous (e.g., periodic) manner.

With regard to FIG. 15, a flow diagram of an illustrative barcode andDWM imaging process 1500 is shown. The process 1500 may start at step1502, where one or more red LEDs may be pulsed ON (e.g., 100 μs pulsesat 80 Hz). At 1504, a monochrome imager may capture images of a scenewhen illuminated by the red LED(s). In an embodiment, a lens for themonochrome imager may be EFL8.66 mm, f #6. In response to the monochromeimager capturing an image while the red LED is illuminating the scene, aprocessor may decode a machine-readable indicia and/or digitalwatermark, as understood in the art. At step 1506, the decodedmachine-readable indicia and/or digital watermark may be output to ahost computer, such as a point-of-sale (POS) computer, for use thereby.For example, the POS computer may apply a cost to an identifierassociated with the decoded machine-readable indicia and/or digitalwatermark.

With regard to FIG. 16, a flow diagram of an illustrative produce anditem recognition process 1600 is shown. The process 1600 may start atstep 1602, where a color image capture request may be made by a host(POS computer) or in response to other events, such as stable weightdetected. At step 1604, (i) one more red LEDs may be turned OFF to avoidimpacting a color image of a scene, and (ii) one or more white LEDs maybe turned ON to fill the scene with multi-spectral illumination. In anembodiment, a pattern generator may optionally be turned ON to help withcapturing a more accurate representation of a shape of produce and/oritem along with helping to eliminate a background (e.g., surface onwhich produce and/or item is positioned). Additionally, a code readermay capture monochrome and/or color images of a scene being illuminatedby the white LEDs, and, optionally, pattern generator. The patterngenerator may be turned ON while the white LEDs are turned ON. In analternative embodiment, the pattern generator may be turned ON while thewhite LEDs are in an OFF state. In an embodiment, the pattern generatormay have a wavelength that is not on a spectral peak of the white LEDsto enable a processor to more easily distinguish a light pattern beingdisplayed by the pattern generator from the illumination of the whiteLEDs.

At step 1606, a 3D point cloud may be calculated based on pre-loadedcalibration data. As understood in the art, a point cloud is a set ofpoints that define external surfaces of an object. At step 1608, itemsize, volume, and/or density may be determined. In determining the size,volume, and/or density, the 3D point cloud data may be analyzed, asunderstood in the art. At step 1610, a region-of-interest (ROI) (e.g.,set(s) of data within a coordinate system) based on the 3D data may beidentified and sent to a recognition engine that is internal or externalfrom a computer on which the process 1600 is being performed. At step1612, the ROI may be communicated to a produce/item recognition engineto determine or estimate a produce or item that is being imaged. Indetermining the produce or item, a learning algorithm (e.g., neuralnetwork) may be used to calculate a certainty value, and one or moreproduce or item possibilities that match the 3D data based on thecertainty value may be presented to an operator for selection therebyvia a scanner or host computer.

With regard to FIG. 17, a flow diagram of an illustrative produce anditem recognition process 1700 using multi-spectral analysis is shown.The process 1700 may start at step 1702, where a determination may bemade if confidence of a recognition result is less than a threshold. Ifso, then at step 1704, multiple spectrum LEDs may be sequentially turnedON, and monochrome images may be captured accordingly. At step 1706, thecaptured monochrome images may be used in recognizing or identifyingproduce or an item that is being imaged by a produce/item recognitionengine. The captured monochrome images may be processed into ancomposite monochrome image with color information as previouslydescribed, and that composite monochrome image may be provided to theproduce/item recognition engine. The identified produce or item(s) maybe communicated back to a scanner or host for use thereby (e.g., add topurchase invoice, display on an interface, enable selection by anoperator, etc.).

One embodiment of a process of a code reader may include capturingmonochrome images of a scene by a monochrome imager. Color images of thescene may be captured by a color imager aligned with the monochromeimager. Stereo 3D images of the scene may be generated from themonochrome and color images.

The process may further include illuminating the scene in which itemswith machine-readable indicia are to be positioned for reading withillumination signals of different wavelengths. Monochrome images may becaptured while illuminating the scene with successive illuminationsignals with different wavelengths.

In an embodiment, a probability of an identity of an item may becalculated based on the stereo 3D image. In response to determining thatthe probability is below a threshold, the successive images may becaptured while illuminating the scene with successive illuminationsignals with different wavelengths to improve the probability ofidentifying the item.

The scene may be illuminated with illumination signals having a commonwavelength. A monochromatic image may be captured while illuminating thescene with the second set of illumination devices. It should beunderstood that a common wavelength may be a range of wavelengths, buthave a single peak wavelength.

The scene may be illuminated with illumination signals having commonwavelengths. A color image may be captured while illuminating the scenewith the illumination signals. It should be understood that commonwavelengths include a range of wavelengths with multiple peaks ofwavelengths.

One embodiment may include capturing corresponding monochrome images andcolor images. A stereo 3D image of the scene may be generated using thecorresponding monochrome and color images. A point cloud based on thestereo 3D image may be generated.

In an embodiment, a light pattern may be illuminated on the scene. Amonochrome image and color image may be captured when the light patternis being projected. The stereo 3D image of the scene including the lightpattern may be generated.

A background surface of the scene in the stereo 3D image may be removed.In an embodiment, a red illumination signal may be illuminated onto thescene to read machine-readable indicia by the monochrome imager. Thecaptured images may be processed to produce a composite image with colorinformation from each of the respective captured images of the scenebeing illuminated with the different wavelengths.

Another method of imaging a scene including produce or items may includeilluminating, over a first time period, the scene with a firstillumination signal. A first monochromatic image of the scene beingilluminated by the first illumination signal may be captured. The scenemay be illuminated over at least one second time period with at leastone second illumination signal with at least one second wavelength.During the second time period, at least one second monochromatic imageof the scene being illuminated by the at least one second illuminationsignal may be captured. A color image may be generated by combining thefirst and at least one second monochromatic images.

Illuminating over at least one second time period may includeilluminating, over a second time period, the scene with a secondillumination signal with a second wavelength. The scene may beilluminated, over a third time period, with a third illumination signalwith a third wavelength. Capturing, during the at least one second timeperiod, a second monochromatic image may include (i) capturing, duringthe second time period, a second monochromatic image of the scene beingilluminated by the second illumination signal, and (ii) capturing,during the third time period, a third monochromatic image of the scenebeing captured by the third illumination signal.

In an embodiment, a third monochromatic image of the scene illuminatedwith ambient light may be captured over a third time period. The colorimage may be calibrated using the third monochromatic image.

The scene being illuminated over at least one second time period with atleast one second illumination signal with at least one second wavelengthmay include illuminating, over at least four second time periods, thescene with at least four second illumination signals with at least foursecond respective wavelengths. Capturing, during at least one secondtime period, at least one second monochromatic image of the scene mayinclude capturing, during at least four second time periods, at leastfour monochromatic images of the scene.

The foregoing method descriptions and the process flow diagrams areprovided merely as illustrative examples and are not intended to requireor imply that the steps of the various embodiments must be performed inthe order presented. As will be appreciated by one of skill in the art,the steps in the foregoing embodiments may be performed in any order.Words such as “then,” “next,” etc. are not intended to limit the orderof the steps; these words are simply used to guide the reader throughthe description of the methods. Although process flow diagrams maydescribe the operations as a sequential process, many of the operationsmay be performed in parallel or concurrently. In addition, the order ofthe operations may be re-arranged. A process may correspond to a method,a function, a procedure, a subroutine, a subprogram, etc. When a processcorresponds to a function, its termination may correspond to a return ofthe function to the calling function or the main function.

The various illustrative logical blocks, modules, circuits, andalgorithm steps described in connection with the embodiments disclosedhere may be implemented as electronic hardware, computer software, orcombinations of both. To clearly illustrate this interchangeability ofhardware and software, various illustrative components, blocks, modules,circuits, and steps have been described above generally in terms oftheir functionality. Whether such functionality is implemented ashardware or software depends upon the particular application and designconstraints imposed on the overall system. Skilled artisans mayimplement the described functionality in varying ways for eachparticular application, but such implementation decisions should not beinterpreted as causing a departure from the scope of the presentinvention.

Embodiments implemented in computer software may be implemented insoftware, firmware, middleware, microcode, hardware descriptionlanguages, or any combination thereof. A code segment ormachine-executable instructions may represent a procedure, a function, asubprogram, a program, a routine, a subroutine, a module, a softwarepackage, a class, or any combination of instructions, data structures,or program statements. A code segment may be coupled to and/or incommunication with another code segment or a hardware circuit by passingand/or receiving information, data, arguments, parameters, or memorycontents. Information, arguments, parameters, data, etc. may be passed,forwarded, or transmitted via any suitable means including memorysharing, message passing, token passing, network transmission, etc.

The actual software code or specialized control hardware used toimplement these systems and methods is not limiting of the invention.Thus, the operation and behavior of the systems and methods weredescribed without reference to the specific software code beingunderstood that software and control hardware can be designed toimplement the systems and methods based on the description here.

When implemented in software, the functions may be stored as one or moreinstructions or code on a non-transitory computer-readable orprocessor-readable storage medium. The steps of a method or algorithmdisclosed here may be embodied in a processor-executable software modulewhich may reside on a computer-readable or processor-readable storagemedium. A non-transitory computer-readable or processor-readable mediaincludes both computer storage media and tangible storage media thatfacilitate transfer of a computer program from one place to another. Anon-transitory processor-readable storage media may be any availablemedia that may be accessed by a computer. By way of example, and notlimitation, such non-transitory processor-readable media may compriseRAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic diskstorage or other magnetic storage devices, or any other tangible storagemedium that may be used to store desired program code in the form ofinstructions or data structures and that may be accessed by a computeror processor. Disk and disc, as used here, include compact disc (CD),laser disc, optical disc, digital versatile disc (DVD), floppy disk, andBlu-ray disc where disks usually reproduce data magnetically, whilediscs reproduce data optically with lasers. Combinations of the aboveshould also be included within the scope of computer-readable media.Additionally, the operations of a method or algorithm may reside as oneor any combination or set of codes and/or instructions on anon-transitory processor-readable medium and/or computer-readablemedium, which may be incorporated into a computer program product.

The previous description is of a preferred embodiment for implementingthe invention, and the scope of the invention should not necessarily belimited by this description. The scope of the present invention isinstead defined by the following claims.

1. A code reader having a hybrid camera, comprising: a monochromeimager; a color imager aligned with the monochrome imager to enable astereo 3D image of the scene to be generated by images captured by themonochrome imager and color imager; and a control circuit operablycoupled to the monochrome imager and the color imager, the controlcircuit configured to operate in different modes including: controllingoperation of the monochrome imager to perform reading of amachine-readable indicia while the color imager is inactive; controllingoperation of the color imager to perform item recognition of an item inthe scene while the monochrome imager is inactive; and controllingoperation of the monochrome imager and the color imager to generate thestereo 3D image to determine a 3D characteristic of the item. 2.(canceled)
 3. A code reader comprising a monochrome imager; a colorimager aligned with the monochrome imager to enable a stereo 3D image ofthe scene to be generated by images captured by the monochrome imagerand color imager; a first set of illumination devices including at leastthree illumination devices configured to output illumination signalswith different wavelengths, and configured to illuminate a scene inwhich items with machine-readable indicia are to be positioned forreading; a control circuit configured to control operation of themonochrome imager and at least three illumination devices to cause themonochrome imager to capture images while illuminating the scene withsuccessive illumination signals with different wavelengths; and aprocessor configured to: calculate a probability of an identity of anitem based on the stereo 3D image; and in response to determining thatthe probability is below a threshold, cause the control circuit tocapture the successive images while illuminating the scene withsuccessive illumination signals with different wavelengths to improvethe probability of identifying the item.
 4. The code reader according toclaim 1, further comprising: a first set of illumination devicesconfigured to output illumination signals at least a first wavelength;and a second set of illumination devices configured to outputillumination signals with at least a second wavelength that is differentthan the first wavelength; and wherein the control circuit is configuredto: cause the color imager to capture an image while illuminating thescene with the first set of illumination devices; and cause themonochrome imager to capture an image while illuminating the scene withthe second set of illumination devices.
 5. (canceled)
 6. (canceled) 7.The code reader according to claim 1, further comprising a patterngenerator configured to illuminate a light pattern on the scene, andwherein the control circuit is further configured to cause themonochrome imager and the color imager to capture the stereo 3D image ofthe scene when the pattern generator is projecting the light pattern. 8.The code reader according to claim 1, further comprising a processorfurther configured to remove a background surface in the stereo 3Dimage.
 9. The code reader according to claim 1, wherein the outputillumination signals of the first set of illumination devices includes awhite color, and the output illumination signals of the second set ofillumination devices includes a red illumination signal.
 10. The codereader according to claim 1, further comprising a processor configuredto process the captured images to produce a composite color image withcolor information aggregated from each of the respective captured imagesby the monochrome imager of the scene being illuminated with thedifferent wavelengths.
 11. A code reader, comprising: a monochromeimager; illumination devices configured to output illumination signalsat different wavelengths; a control circuit in electrical communicationwith the monochrome imager and the illumination devices, the controlcircuit configured to independently drive the different illumination tocapture images of an item in the scene when exposed to the illuminationsignals at different wavelengths; and a processor in communication withthe control circuit and monochrome imager, and configured to: receivethe captured images from the monochrome camera and produce a compositecolor image with color information aggregated from each of the capturedimages by the monochrome imager when illuminated by the differentillumination signals; and identifying the item from the scene based onthe composite color image.
 12. (canceled)
 13. The code reader accordingto claim 11, wherein the control circuit is further configured to causethe monochrome imager to capture an image with ambient light when noneof the illumination devices are being actively illuminated, and whereinthe processor is further configured to offset the composite color imagewith the image captured with ambient light.
 14. The code readeraccording to claim 11, wherein the images of the item captured with eachof the different illumination signals are captured with the item beingin the same, stationary position.
 15. A method, comprising: capturingmonochrome images of a scene by a monochrome imager while a color imageraligned with the monochrome imager is inactive for reading amachine-readable indicia of an item in the scene; and capturing colorimages of the scene by the color imager while the monochrome imager isinactive for item recognition of the item; and generating stereo 3Dimages of the scene from the monochrome and color images captured whenboth the monochrome imager and the color imager are active fordetermining a 3D characteristic of an item in the scene.
 16. The methodaccording to claim 15, further comprising: illuminating the scene inwhich items with machine-readable indicia are to be positioned forreading with illumination signals of different wavelengths; andcapturing monochrome images while illuminating the scene with successiveillumination signals with different wavelengths.
 17. The methodaccording to claim 16, further comprising: calculating a probability ofan identity of an item based on the stereo 3D image; and in response todetermining that the probability is below a threshold, capturing themonochrome images while illuminating the scene with successiveillumination signals with different wavelengths to improve theprobability of identifying the item.
 18. (canceled)
 19. The methodaccording to claim 15, further comprising: illuminating a light patternon the scene; capturing a monochrome image and a color image when thelight pattern is being projected; and generating the stereo 3D image ofthe scene including the light pattern from the monochrome and the colorimage.
 20. The method according to claim 15, further comprisingprocessing the captured images to produce a composite color image withcolor information aggregated from each of the respective captured imagesby the monochrome imager when the scene is illuminated with thedifferent wavelengths.
 21. The code reader according to claim 1, whereinthe monochrome imager and the color imager have different resolutions.22. The code reader according to claim 1, wherein exposure of the colorimager is longer than exposure of the monochrome imager.
 23. The codereader according to claim 1, wherein the item is a produce item.
 24. Thecode reader according to claim 11, wherein the different wavelengthsinclude green, blue, and red wavelengths.
 25. The method according toclaim 15, further comprising transforming captured color image data fromthe color imager from a color data format to a monochrome data formatprior to generating stereo 3D images of the scene from the monochromeand color images.